I would have to imagine yes, but this is hard to find information on given the hundreds of pages of FBI docs
If you're part of an intellectual tradition that somehow managed to survive the cold war without being shot at by the pigs you're either compromised or so unthreatening that you might as well be
Right, and compromised does not always mean a rat, but easily can be people who the feds have found useful for tracing other leftists, etc
Yes. I wish I had something more concrete than anecdotes, but on the old reddit there were post every now and then about authorities snooping on people's DSA chapters and of the strings of the arrest you see after every major protest in the US are likely at least partly due to informants. The DSA did not even ban cops from being members until like 2020.